Great tips -- I have some very small plastic zip bags (I think they are for embroidery floss) and I can put the smaller spool and bobbin in. For the larger spools, I use bags that are a bit larger (from Michaels I think). I use plastic boxes for the thread since I ran out of drawer space a long time ago.

I have plastic storage, got several from connecting thread and others at Wal Mart a long time ago, everything gets dusty here with the dogs, and I can put bobbin on top of spool in case. Rubber band idea is great but here in FL they would not last too long, heat seems to get them.